i was wondering if i can put aftermarket parts on my 2011 Civic siwhile its still under warranty?

 

that depends on the parts... brake rotors or pads are fine as they are consumable parts...intakes and suspension pieces are not as they are warranted and are covered...

 

How about an exhaust?

 

Cat back are not a problem, change the header and the complete exhaust or do a cat delete ( test pipe) and you will have problems as they mess with the ECM.

 

This question regularly appears, and is usually answered incorrectly.

You can use any aftermarket parts on your warrantied car that you want. Obviously, the car's warranty won't cover parts that it didn't come with, but the rest of the parts that had a warranty still keep the warranty.

Your warranty can't be voided for aftermarket parts. Ever.

However, a claim can be denied if something you did caused a warrantied part to fail, but the burden of proving that the modification did this is on the dealership / Honda.

Run smaller fuel injectors that make the engine run lean, and the resulting detonation damages the engine, expect the warranty claim to be denied, but the warranty is not voided, and everything else on the car still keeps its warranty coverage.

The answer to the OP's question is "yes".